Sealing device



Oct. 26, 1937. H. HORNSCHUCH' 2 96,

SEALING DEVICE Filed Aug. 7, 1935' 2 Sheets-Sheet 1 INVENTOR h Hannfibamaa/zuak. N W aw' HIS ATTORNEY.

0ct.26,1937., HORNSCHUCH 2,o9',899"- SEALING DEVICE Filed Aug. 7, 1935 2 Sheets-Sheet 2 .INYVENQTOR. v I

Han Hornadwafi 1 BY -1 HIS ATTORNEY Patented Oc t. 26, 1937 UNITED A P ENT 7 SEALING DEVICE Harms Hornschuch','Easton; Pa., assignorbto Ingersoll-Rand Company, Jersey City. N. J., a corporation of New Jersey Application August '1, 1935, SerialNo. 35.082

This invention relates to sealing devices, and more particularly to asealing device for a rotary member; as for example the shaft of a centrifugal pump.

5 One object of the invention is to assure a true sealing contact between the elements intended to effecta seal.

Another object is to augment the means normally relied upon for maintaining'a seal during 10 such conditions f-of operation of the pump as might tend to cause a breach between the sealing members. g 1

Still another object is to enable such augmenting force to'be automatically "applied and removedin accordance with variations in the operating speed of'the piunp. v g

Other objects will be in part obvious and in part pointed out hereinafter.- In the drawings accompanying this specification and forming a-part,thereof "Figure 1 v is a longitudinal elevation, partly broken away, of a pump equipped with a sealing device constructed in accordance with the'practice of the invention, and e3 Figure 2 is an'elevation, in section, of the sealing deviceand a portion of the pump.

Referring to the drawings, and at first more particularly to Figure 1, designates a pump of the centrifugal type and 2| a motor connected 30 to a shaft 22 of the pump for driving the rotary elements of the pump.

The shaft 22 carries afgearj23 which meshes with a driving gear 24. of a pump 25, shown as being a gear pump, for pumping lubricant under 35 pressure to the various bearing surfaces ofthe pump requiringlubricant; The intake side of the pump 25' is connected, by a conduit 26, with an oil reservoir l9, and'the discharge output of the pump 25 is conveyed therefrom by av conduit 21 having suitable branches to connect it with points in the pump 20 requiring lubrication."

The ends of the casing of the pump 2ll eonstitute stuffing boxes through which the shaft 22 extends loosely. In Figure 2 is shown the stuffing box 28 adjacent the discharge side of the pump 20, and on the portion of the shaft 22 lying, within the stuffing box 28 is a sleeve 29 which is secured to the shaft 22 by a key 30 so that the sleeve 29 will rotate with the shaft. In the. outermost end of the sleeve 29 is an internal recess 3| containing packing material 32 which encircles the shaft 22- and is compressed by a sleeve 33 threaded on the shaft 22, asindicated at 34.

The outer end of the sleeve 23 may constitute I a sealing surfacev 35' or, as,illustrated, a seat-for the innermost of a series ;of rings 36 disposed about the'zsleeve 33 to provide renewablesealing surfaces whenever :an active: surface =35 becomes worn 'or otherwiseunfitfor maintaining. agsea-L.

Extending into the outer. end of the, stufilng box .28,- in order to centralize-it therewith, isza sleeve 31 having, a lateralyflange 38 which seats against the end of the stufli ngbox andlies .within a recess 39 of a platev 40 secu'redto the stuffing box, as by bolts 4-l,:-for'clamping the sleeve31 in' position. In theouterendof the sleeve 31; isian enlarged bore or recess 42 containing a, ,com-' pressible packing member. 43 which is interposed betweenrings 44 and 45." 1

The ring 44 is'seatediin the bottom of therecess 42, and :the,:ring 45 extends part way beyond the end offthesleeve 31 and abuts a shoulder 46 on a gland41encircling the'shaft 22.: The gland 41 is-secured to the plate .40 by bolts '-48 and has a bore 49 in its inner end to'receivethe 'end" of the sleeve 31 for centralizing the two :with respect to eachother; v

The inner surfaces of the rings 44 and 45 serve as guiding surfaces for a sealing member 50 shown: as being inthe form of a sleeve having a bore of slightly larger. diameter than the adjacent portion of the sleeve 33 which it encircles toiavoid contact between the two. Upon being com- 1 pressed, the packingmember 3 136918 vagainst the periphery of the sleeve 50 to effect a seal: at that point and, by seating'againstthe peripheral surfaceof the recess 42, to prevent leakageof fluid over the outer surfaces of the rings and The inner end of thesleeveillv constitutesa sealing surface .5l; whichcooperates withthe adjacent sealing surfaces- 35 to-prevent" leakage I of liquid from the interior- 52 of the stufling -box and which interior may be in free comr'nunication with the discharge .endof the pump' 20; The'sealingsurface 5| is co-extens'ivewith the 7 ends of the sleeve 50 and a lateralflange*-53 on the sleeve 50. :2:

The opposite side of the flange 53 serves as a 45 seat for a spring'54 interposed between the flange 53 and the ring 44 and acting constantly to press the sealing surface f5l into sealing relationship with the adjacent sealing surface 35.1 In itsassembled position the". spring 54 is'initially com- =.50

pressed by the gland 41 so that said spring-exerts aconstant pressure against the flange foithe purpose set' forth." e I I The sleeve 50,1while it may move longitudinally of the snartizz, is 'non-rotatableand isf heids against such movement by a pin 55 seated in the gland l1 and extending into a longitudinally extending slot 56 in the sleeve 50.

In practice, it has been found that an effec- "tive seal maybe maintained between the cooperating surfaces of relatively rotary and stationary members, such as the sleeve ill and the rings It, by the force of the spring [4 during the normal operation of the pump, that is, during such'times as the pump is operating at normal speeds. The sealing surfaces and I, being initially con- 'structed for maximum contact with each other and seated against each other, to exclude solids entrained in the liquid being pumped, will remain in sealing engagement with each otherjand prevent leakage of liquid between their cooperating surfaces. It has been found, however, that during certain periods of operation, for example during the starting period of the pump, the pump shaft vibrates to such an extent that the parts constituting surfaces are shifted in sufficient degreewith respect "to each other to provide an opening between the sealing members, thereby making it possible for solid particles to be trapped'between them.

The sealis then; of-course, broken, and during the subsequent operation of the pump large quantitles of liquid will pass directly from the pump through-the sealing device and along the shaft to the exterior of the pump. It is accordingly contemplated to augment the force of the spring It for preventing separation of sealing members during such periods of vibratory movement of the shaft 22 and to cause'the augmenting force to be automatically applied to and removed from the sleeve I. inaccordance with the occurrence or non-occurrence of the foroetending to break sealing engagement between the sleeve I. and

-.the surface against which it seats.

In furtherance of thiszend the gland n is mvidedwithan extension II to serve as a guide for a collar ll disposed slldably thereon and having an annular shoulder]. whichis adapted to seat against the end of the sleeve 80.. The collar II encircles .the shaft 22, and in the inner surface or an extension '00 of the collar arranged packing members "which seatZIID n the surface h The collar It is capable of reciprocable moveof the sleeve SI.

" In the end of the collar is adjacent the sleeve I0 is arecesst! andapassage II on the collar. connects the recess .2 with the conduit N,

threaded into thecollar, to provide an outlet for such'slight amounts of liquid as may pass between the sealing surfaces II and ll.-

ment ontheextension; l1, but is held against 1 rotary movement with respect thereto, in the present instance, by a pinllwhich is amxed to the gland" and extends into an aperture is in the adjacent faceof the collar". The collar may-be additionally heldagainst rotary movement by bolts "extending into sockets se in the collarand being threaded through the ends of a yoke u whereby the collar 50 is actuated.

Theyoke is is mounted upon a pivot" seated in or-arms'll of abrack et 12 secured to the plate as by bolts [8. The bracket .12 has anextensionll which is arranged in substantial parallelism with the shaft and supports at its outer end a cylinder "having a piston chamber rection, and on the other end of the piston is a stem 19 which extends slidably into a recess ll in the bracket 12.

Within the stem 19 is a slot 8| through which extends a lever 82 forming an integral portion of the yoke 59, and on the portion of the lever 82 lying in the plane of the slot is mounted a roller 83 which is adapted to bear against end surfaces 84 and I! of the slot ll, accordingly as the piston 'I'I moves in one direction or the other.

' The lubricant under pressure acting against the pressure area 18 is opposed by a spring 8' disposed in a recess 81 in the stem It, The tension of the spring 86 may be controlled by a screw 88 threaded into the bracket 12 and carrying on its inner end a plate as which serves as a seat for the spring OI. V p

In order to limit the distance which the piston 11 may actuate the yoke 89 for moving the collar I8 out of contact withthesleeve N, a screw ll is threaded into the bracket to extend withits leading end ll. into the path of the lever 02. The

screw 90 may be adjusted, as required, to determine the clearance between the sleeve Ill and the shoulder so of the collar 58 in the releasing .flrmly thereagainst during the'submuent starting and accelerating period ofthe pump 2|.

The spring It willthus augment the pressure of the spring H for maintaining the sealing surface ll seated firmly against the adjacent sealing surface ll. During the accelerating period of the pumps "and II, and at which time r mp shaft 22 is subjected to the vibratory movement hereinbefore stated, the collar I. remains in this position until the valueof the pressure 1 in the lubricating system approaches that maintained during the normal operation of the pump fl, that is, when the pump 2| ap-, proaches or reaches normal The lubricant under pressure then acting against thepressure area ll will predominate over thatexerted by the spring 88, and the lever s: will be rocked against the end I of the screw 90. Inthis position of the-lever the pressure (I the yoke a is removed from'the collar II which may then move out of engageme'nt'with the ill, and the spring 54 be ableto maintain the sealing surfaeefll in full. sealing engagement with the sealing surface II. 7

As will be readily seen. therefore, the augmenting pressure of the spring 88 is only applied to the sleeve 50 during the comparatively short period of starting of the pump'fl so that the sealing. surfaces BI and 35 will not be subjected to the rapid wear which would result by employing a spring 54 of sufiicient strength to prevent separation of the sealing surfaces II and ll under all conditions of operation of the pump.

The collar 58 remains disengaged from the g Q sleeve 50 as long as the pressure in the lubricating system approximates the value relied upon for effecting efficient lubrication and while the pump 20 is operating at normal speeds. However, shortly after the beginning of a decelerating period of the pump, as when it is intended to stop its operation so that the pressure in the lubricat- I" ing system again decreases, the spring 86 will again rock the yoke 69 and press the collar 58 against thesleeve 50. In this way the spring 86 and the collar serve to prevent the separation of the sealing surface from the sealing surface 35 v during the startingand stoppingperiods of the rotor for determining the degree of sealing pressure between the sealing surface and the sealing member.

2. In a sealingdevice, the combination of a casing and a rotor, a sealing surface on the rotor, a sealing member slldable in the casing to cooperate with the sealing surface for preventing leakage of fluid from the casing, a spring for constantly maintaining the sealing member in sealing engagement with the sealing surface, means for augmenting the force of the spring, and pressure responsive means for controlling the first said means.

3. In a sealing device, the combination of a casing and a rotor, a sealing surface on the rotor, a sealing member slidable in the casing con-' stantly cooperating with the sealing surface for preventing leakage of fluid from the casing, a

spring for constantly pressing the sealing member into sealing relationship with the sealing surface, means for augmenting the pressure of the spring; and pressure responsive means for rendering the first said means'non-eifective.

' 4. In a sealing device, the combination of a casing and a rotor, a sealing surface on the rotor, asealing member slidable in the casing to cooperate with the sealing surface for preventing leakage of fluid from the'casing, a plurality of springs for pressing the sealing member against the sealing surface and one of said springs constantly acting to hold the sealing member in sealing relation with'the sealing surface, and pressure responsive means for controlling the pressure of the other spring.

5. The combination of a rotary shaft with a sleeve having an annular recess at one end thereof and encircling said shaft and rotatable therewith, packing material in the recess in contact with the shaft, a second sleeve to compress said packing material and to hold the first sleeve against axial movement, a third sleeve encircling the second sleeve held against rotation therewith, a sealing element between the adjacent ends of the first and third sleeves, a collar slidably mounted upon the shaft and adapted to bear against the third sleeve, and pressure responsive means to control the pressure exerted upon the third sleeve by said collar.

mums HORNSCHUCH. 

